Function push

kernels/common/instance_stack.h:23–51

 */
template<typename Context>
RTC_FORCEINLINE bool push(Context context,
                          unsigned instanceId,
                          unsigned instancePrimId)
{
#if RTC_MAX_INSTANCE_LEVEL_COUNT > 1
  const bool spaceAvailable = context->instStackSize < RTC_MAX_INSTANCE_LEVEL_COUNT;
  /* We assert here because instances are silently dropped when the stack is full.
     This might be quite hard to find in production. */
  assert(spaceAvailable);
  if (likely(spaceAvailable)) {
    context->instID[context->instStackSize] = instanceId;
#if defined(RTC_GEOMETRY_INSTANCE_ARRAY)
    context->instPrimID[context->instStackSize] = instancePrimId;
#endif
    context->instStackSize++;
  }
  return spaceAvailable;
#else
  const bool spaceAvailable = (context->instID[0] == RTC_INVALID_GEOMETRY_ID);
  assert(spaceAvailable);
  if (likely(spaceAvailable)) {
    context->instID[0] = instanceId;
#if defined(RTC_GEOMETRY_INSTANCE_ARRAY)
    context->instPrimID[0] = instancePrimId;
#endif
  }
  return spaceAvailable;
#endif
}

/* 
 * Pop the last instance pushed to the stack.